Manual / Guide · 1965
The 161-page factory service manual for the four-counter EC-130: theory of operation down to gate level, the delay line and its amplifiers, the counters, every keyboard function as a flow chart, the display circuits (segment, dot and staircase generators, slant and deflection amplifiers, diode matrix), the power supplies including the -2,400 V multiplier, and adjustment procedures.
178269394S!21e 0079! 35081 1.31 00002! 8631449 oogo0g04!1 551.36 ELECTRONIC CALCULATOR 130 SERVICE MANUAL Friden, sac SAN LEANDRO - CALIFORNIA A SUBSIDIARY OF THE SINGER COMPANY TP-158SL-1 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com COPYRIGHT 1965 BY FRIDEN, INC. A subsidiary of Singer Company Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL TABLE OF CONTENTS SECTION 1. GENERAL DESCRIPTION SCOPE OF MANUAL ........ ELECTRICAL CHARACTERISTICS. ......... PHYSICAL CHARACTERISTICS ........... OPERATIONAL DESCRIPTION. ........... DISPLAY 3 i i cee a el 8 aw we Be ee ew DECIMAL POINT SELECTOR, ..........6.6+. SERVICE CALLS ........ ae teee wee mse CUSTOMER CONTACT ie; « 0 16: 6 1 io: © me yon ee mw ie MACHINE CHECKOUT .......... ei SERVICING DOCUMENTATION. .......+8.6+5 COMPUTER PRINTOUT (MDD)........... LOGIC BLOCK DIAGRAM. .. . 6 se see ene ENGINEERING DRAWINGS........ @ lat we SERVICE LETIERS 4 is i og 6 9 @ 46 WEDS ES SERVICE RECORDS ........ oe © we © SECTION 2. ANALYSIS OF OPERATION FUNCTIONAL DESCRIPTION. .......---.-- DATA ORGANIZATION. ..... TT TITTY BASIC TIMING .......----+2 02 eee TIMING CHAIN... ....--2 0000 eee COUNTER CIRCUITS... ..-..--02000- DATA GHIPTING 4c cccs ex wus wea wees DELAY TINE GCIROUTES sw ca wis was wise Mon mssmscaen ue Lee eee FUNCTION CONTROL ......----2----- WAY ccc mee ecm scam ee (IROL AR CIROUITE: w cs es ew gee ce we wc BARIG DIRODEE cc p cs we ewe RE Rw E HS FLIP-FLOP... 0... 00 eee eee eee TOUTE, ok ce ee eek ee ew EMITTER- FOLLOWER. 2. 06-0 ee eee Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com PAGE di FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL PAGE COUNTER CIRCULS 2. 28ims% See S BS KS 2-12 COUNTING: 25 Gi S5 SEEGERS BER dines ax 2-12 DATAUSHIN TING «2 ms 4 ck eam EB we ew 2-15 DELAY DINE CIRCUITS’: «2s ewes wee we oes 2-21 DELAY LINE 4 6) 64 6S 68 HSE SESE ES 2-21 TRANSDUCERS... 1.2... 2.2 eee eevee 2-21 READ AMPLIFIER ..........+.. 0040s 2-22 WRITE HOGI. oe: oo we oe ew GE eRe Te 2-24 WRITE: AMPLIBTER: is: ¢ = wi & 8 i BS wR KS 2-25 BASIC LOGIC 23 88 9S HERES mie me perne 2-27 ORGATE..... ee ee ee ee ee 2-27 AND'GATE, io: 2 6 eo ve HO @ WKS @ Rm HOH 2-28 AGIGATE «usu wee KE GOES HS BiG SS 2-28 LOGIC NETWORKS.............6.0-02. 2-30 LOGIC EQUATIONS. ...........000004 2-31 eG CN na ee RO ee ee Oe 2-32 OSCILGATBOR « a si ac ws oe we SES BERR BS 2-32 MACHINE START 6 6 666 8 Wea Sew ewe ne 2-33 FUNCTION START ..........-2.0000. 2-33 BET COUNTER, 9 ece: = a 6 & me KO Oh ww 2-34 REGISTER COUNTER. . 2. ee bre es F 2-36 COLUMN COUNTER: 52 #8 §% 82626 PRE BES 2-36 ROGIC CONTROL 6 iw ss BER DES BRE RE woe 2-40 ENTRY PHASE COUNTER(EPC),......... 2-40 DECIMAL POINT COUNTER (DPC) ........ 2-42 PUNGTION LOGO omicae ee we 8% ESE ES 2-45 BD a: ees ERE ETRE BRE RE aw eam: 2-45 SUBTRAGT 6 cs WEE REL Gene nee ame 2-51 MULTIPLY ..........20.00000 eae 2-59 Peed Ame ne oe E ee BUR © mK SRA & eS 2-71 NUMBER ENTRY oo cx: 6 swe eu i 8% 8 RUS HS 2-82 REPEAE eg 4 6 26 BLED REE Ree weve 2-85 RECALL © ii es ERE kw eww eer emunn 2-86 STORE... 1... . eee tee ee ee ee ee 2-88 CLEAR ENTRY. 0. «exe: & a: % @ mH BI EH BEE 2-89 CUANGE SIGN: ss sis sa SERRA Dew eax 2-90 CLEAR ALL.............0.00000004 2-92 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL PAGE DISPLAY DEFLECTION . 6 1 20 6 se 6 ewe ewe 2-94 SEGMENT GENERATOR ...........2..4. 2-95 DOT GENERATORS «: 23 6 fe Be eG ke ER SS 2-96 SLANT AMPLIFIER. ..........-2.22-4- 2-98 VERTICAL STAIRCASE GENERATOR....... 2-98 HORIZONTAL STAIRCASE GENERATOR ..... 2-100 DEFLECTION AMPLIFIERS ............ 2-102 DISPLAY BLANKING .... 2... ee ee eevee 2-104 UNBLANKING INVERTER ........-2e+6-. 2-104 DIODE: MATRERs 6 6 v6 eee % 6 @ BB wr ew we 2-104 DISPLAY TIMING AND LOGIC ............ 2-110 DISPLAY TIMING. ... 2... eee eee eevee 2-110 DISPLAY GOGIC « w i a 26 isi & em: © wow 6 we ew 2-112 POWER SUPPLIES i 6 wi vo we & 6 tH & wR 6 KR BS 2-116 +6: VOLT SUPPLY « i & 64 § S56 2 ow FH ee ew 2-116 “12 VOLT SUPPLY & oi bb ye BS oa 6 Bl 8 se! SB ee 2-117 “80 VOLT: SUPPLY . 0: « «0 Cee te ee , 2-117 #2400 VOLT SUPPLY «eae e ane eae woe ew 2-118 GRE VOLTAGES ¢ 4 it 6 5% ee wR wT we 2-119 KEYBOARD FUNCTION. ......-.6-2 222 eo 2-121 GENERAL DESCRIPTION. ............. 2-121 CODE BARS i vw 0; 6 % 12 6% vay How a Hw wer Se we ww Ue 2-121 KEYBOARD INTERLOCEK:. «sh & owe HE aS 2-122 REED SWITCHES « «8 % we ewe ewe we ew 2-122 KEYBOARD ELECTRICAL FUNCTION. ...... 2-124 SECTION 3. ADJUSTMENTS SCOPE OF SECTION 4 es @ ESLER GS ws 3-1 KEYBOARD ADJUSTMENTS ...... 2+ ee eee 3-1 EQUIPMENT REQUIRED. ......-2-+ 22+ 3-1 INITIAL: PROCEDURE 2 2 0 0 we 6 we wwe were 3-1 CD REED SWITCH « a: s a va 6 eee we ew wD we ww s 3-3 DIGIT KEY REED SWITCH. ........2.4.-.2-. 3-3 CF REED SWITCH ... ee ere ee ee nene 3-4 FUNCTION KEY REED SWITCH .........-. 3-4 CODE BAR ADJUSTMENT ......4.-+.-+44.-. 3-4 INTERLOCK ASSEMBLY ADJUSTMENT. ..... 3-6 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com iv FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL CHARACTER ADJUSTMENTS. ..........2.. SEGMENT LENGTH. .......205620250 2026. CHARACTER WIDTH... « cece om © ie © wR Rw ay CHARACTER HEIGHT «106 8 6 6 @ @ HH ww i DISPLAY ADJUSTMENTS. ...... 6s ee eeee HORIZONTAL CENTERING ............ VERTICAL CENTERING ..........2.+.4.. HORIZONTAL CHARACTER SPACING. ...... VERTICAL CHARACTER SPACING ........ READ AMPLIFIER GAIN ADJUSTMENT....... SECTION 4. MAINTENANCE KEYTOP REMOVAL AND REPLACEMENT... DECIMAL POINT SWITCH REPLACEMENT... . INTERLOCK ASSEMBLY ADJUSTMENT..... CODE BAR ASSEMBLY REPLACEMENT ..... CODE BAR IDENTIFICATION ........... KEYSTEM IDENTIFICATION. .....-...... Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com PAGE 3-7 3-7 3-7 3-8 3-8 3-8 3-9 3-10 4-1 4-1 4-2 FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL LIST OF ILLUSTRATIONS NOTE: Figures not in chronological order with the text are Foldouts and will be found at the end of each section. FIGURE PAGE 1-1 ELECTRONIC CALCULATOR 130 ........2e+.0-e066 td 1-2 KEYBOARD ARRANGEMENT... 2. es erecereerves 1-2 2-1 OVERALL BLOCK DIAGRAM ...... 22.20 s es eees 2-128 2-2 DATA ORGANIZATION . 1... ce ecw ee ete twee 2-1 2-3 DISPLAY ORGANIZATION ... 2.2 eevee rcnrnncvens 2-2 2-4 TIMING, FUNCTIONAL DIAGRAM ........56.+6+04- 2-2 2-5 DISPLAY SHIFTING. . 2. 2 eee te te te wt ww es 2-4 2-6 DATA SHIFTING 2... -.6 6 68 6 8 ERS REDE MESS ES 2-4 2-7 DELAY LINE, FUNCTIONAL DIAGRAM ..........4.. 2-5 2-8 BASIC CHARACTER FORMATION .......-+424 50685 2-8 2-9 BASIC FLIP-FLOP CIRCUIT...... Sie BOW OT We ww GE wi % 2-10 2-10 BASIC COUNTER, FUNCTIONAL DIAGRAM.......... 2-13 2-11 DIGIT COMPLEMENT, FUNCTIONAL DIAGRAM ....... 2-14 2-12 SHIFT UP OR LEFT, FUNCTIONAL DIAGRAM ........ 2-17 2-13 SHIFT DOWN, FUNCTIONAL DIAGRAM ............ 2-18 2-14 IDLE CONDITION, FUNCTIONAL DIAGRAM.......... 2-20 2-15 DELAY LINE, PHYSICAL ARRANGEMENT .......... 2-20 2-16 TRANSDUCER, FUNCTIONAL DIAGRAM ........... 2-22 2-17 READ AMPLIFIER SCHEMATIC ..... 2.1 eee eevee 2-23 2-18 WRITE AMPLIFIER LOGIC... .. 2.5 ee ee eer e nee 2-24 2-19 WRITE AMPLIFIER SCHEMATIC. ........-2-+-+4+2e+8- 2-26 2-20 AC GATE, WAVEFORMS....... SVT TIPTIC TING 2-29 2-21. LOGIC NETWORK .: » «i 0 ee se ee ete eee em ee ee 2-30 2-22 MASTER OSCILLATOR SCHEMATIC. .......-4+58665 2-32 2-23 START LOGIC... .. + ee sees vsve ee ee 2-33 2-24 BIT COUNTER LOGIC. .. 1.2.21 ee eee eer eee tw eee 2-35 2-25 REGISTER COUNTER LOGIC. ....- 2s ee eee ee ees 2-37 2-26 COLUMN COUNTER LOGIC... 2... eee ee eet ee eee 2-39 2-27 ENTRY PHASE COUNTER (EPC)....... aw ey we ase oe e 2041 2-28 DECIMAL POINT COUNTER (DPC)... 1... +++ eee ees 2-43 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com ve FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL FIGURE PAGE 2-29 ADD FLOWCHART...........00+ 000 eevaee 2-129 2-30 SUBTRACT FLOWCHART............000000, 2-130 4°31 MULTIPLY FLOW CHART inci seu HERDER SES 2-131 2-32 DIVIDE FLOW CHART .........00000000 cece 2-132 2-33 DIGIT SELECTION LOGIC ............0+.e400e 2-83 2-34 DIGIT SELECTION FLOW CHART............... 2-133 2«30 ENTER PLOW CHART. wks cee aw tn wee ee wee ees 2-134 2-36 REPEAT AND RECALL LOGIC............-000.0. 2-87 2-37 REPEAT AND RECALL FLOWCHART............. 2-135 2-38 CLEAR ENTRY AND STORE LOGIC .............. 2-89 2-39 CLEAR ENTRY AND STORE FLOWCHART.......... 2-136 2-40 CHANGE SIGN LOGIC AND FLOW CHART. .......... 2-91 2-41 CLEARALL LOGIC ..............00000004 2-93 2-42 DEFLECTION CIRCUITS, COMPOSITE BLOCK DIAGRAM .. 2-137 2-43 SEGMENT GENERATOR SCHEMATIC ............. 2-94 2-44 SEGMENT SWITCHING SCHEMATIC.............. 2-95 2-45 VERTICAL DOT GENERATOR SCHEMATIC.......... 2-96 2-46 HORIZONTAL DOT GENERATOR SCHEMATIC ........ 2-97 2-47 SLANT AMPLIFIER SCHEMATIC. .............0.. 2-98 2-48 VERTICAL STAIRCASE GENERATOR SCHEMATIC...... 2-99 2-49 DEFLECTION VOLTAGE RELATIONSHIPS .......... 2-138 2-50 HORIZONTAL STAIRCASE GENERATOR SCHEMATIC .... 2-100 2-51 HORIZONTAL DEFLECTION AMPLIFIER SCHEMATIC... . 2-102 2-52 VERTICAL DEFLECTION AMPLIFIER SCHEMATIC ..... 2-103 2-53 UNBLANKING INVERTER LOGIC ............... 2-105 2-54 DIODE MATRIX SCHEMATIC. .............. » +. 2-106 2-55 MATRIX LOGIC..............2.2-0000004. 2-108 2-56 COMPARE SIGNAL LOGIC ..............2.. «. 2-111 2-57 DISPLAY LOGIC ..........0.0004 ee eeeae. 2-112 2-58 DECIMAL POINT SWITCH LOGIC ............... 2-114 2-59 POWER SUPPLY SCHEMATIC ................. 2-116 2-60 +6 VOLT SUPPLY SCHEMATIC ................ 2-117 2-61 -12 VOLT SUPPLY SCHEMATIC................ 2-118 2-62 -80 VOLT SUPPLY SCHEMATIC................ 2-119 2-63 -2400 VOLT SUPPLY SCHEMATIC......... c+ ee ee 2-120 2-64 MAGNET-REED SWITCH ACTION. .............. 2-123 2-65 KEYBOARD DELAY (KBD) SCHEMATIC............ 2-124 2-66 OVERFLOW LOGIC AND INTERLOCK COIL SCHEMATIC. . . 2-126 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com — FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL FIGURE S-I KEYBOARD TESTER i ck wise SHED EER THC EEwWERG 38-2 KEYBOARD TESTER LAMP CHART...........266-. 3-3 VOM ADAPTER SCHEMATIC... ......+000 508+ 3-4 VOM ADAPTER LAMP CHART. ......00800800486 3-5 REED SWITCH SADDLE ADJUSTMENE ......... eee 3-6 KEYSTEM ECCENTRIC CAM ADJUSTMENT. ......... 3-7 CODE BAR LIMIT SCREW ADJUSTMENT ........... 3-8 INTERLOCK MAGNET LATCH ADJUSTMENT. ........ 3-9 CHARACTER ADJUSTMENT CONTROLS. ........... 3-10 DISPLAY AND CHARACTER DIMENSIONS. .......... 3-11 DISPLAY ADJUSTMENT CONTROLS. .......-..-208. 3-12 READ AMPLIFIER ADJUSTMENT ........2025e006 3-13 READ AMPLIFIER ADJUSTMENT LEVEL........... 4-1 KEYBOARD MASK...... ee ee ee ees ce eee 4-2 KEYTOP REMOVAL. . «2.265 eee eae é Teo em RDO w Ve 4-3 KEYTOP REPLACEMENT, PRELIMINARY .......... 4-4. KEYTOP REPLACEMENT, FINAL...........-40.2.4. 4-5 DECIMAL POINT SWITCH REPLACEMENT.......... 4-6 INTERLOCK ASSEMBLY ADJUSTMENT..........4.. 4-7 KEYBOARD INNER PARTS PLACEMENT ........... 4-8 CODE BAR IDENTIFICATION CHART ........-+.4.4.. 4-9 KEYSTEM IDENTIFICATION. .....-.-2-2¢ 222+ eee, 4-10 KEYBOARD TOP INSTALLATION .........-+.+..--. Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com vit ~~ 9-1-65 FRIDEN ELECTRONIC CALCULATORS SECTION 1 EC-130 SERVICE MANUAL SECTION 1 - GENERAL DESCRIPTION A. SCOPE OF MANUAL This manual covers the maintenance of the EC-130 (Figure 1-1). The maintenance of the EC-130 requires extensive ‘and thorough know- ledge of the machine, especially as to logic func- tions. While most troubles are of a component failure nature, localization of the trouble to a particular component may involve extensive trac- ing of logic signals through the plug in circuit cards. Since the EC-130 uses dynamic storage, and the logic actions are predicated upon time through the timing chain and Entry Phase Counter, know- ledge of machine timing and proper use of a Tektronix 535 Oscilloscope (or equivalent) is nec- essary. B. ELECTRICAL CHARACTERISTICS The EC-130 operates on 115V +10% AC, 50-60 cycles, and may be connected to any standard AC outlet. Specially designated machines for export only are designed for operation at 220 VAC. The EC-130 is fused internally with a 1 Am- pere line fuse and a 2 Ampere fuse in the -12 VDC power supply output. C. PHYSICAL CHARACTERISTICS The EC-130 is 22" long, 18" wide, 10" high, and weighs approximately 45 lbs. The relatively small size of the EC-130 makes it suitable for placement on any standard office desk, and the light weight makes it truly portable. D. OPERATIONAL DESCRIPTION The operation of the EC-130 is controlled by an ON-OFF switch lever located on the lower front right-hand side. Once the lever has been placed to ON position and the display appears on the CRT, the EC-130 is ready for keyboard control. 1. DISPLAY The display on the EC-130 consists of four 13- digit registers, each with an algebraic sign col- umn. No sign displayed means a positive number in that register. If the number is negative, a minus sign is displayed in the extreme right- hand position of the register. The EC-130 employs a new concept in compu- tation which permits storage of intermediate answers for later use according to the require- ments of the problem being solved. The four reg- isters are specified and arranged in a particular manner. (See Figure 1-1.) a. REGISTER #1. The lowermost register is des- ignated as Register 1, also known as the “An- swer Register”. All numbers enter the display through this register, and are displaced upward by subsequent entries. At the finish of any arith- metic function, the answer to the computation appears in Register 1. This register is also brightened with respect to the other registers. R4 R3 DISPLAY R2 R14 ON-OFF SWITCH (HIDDEN) KEYBOARD Figure I-1. Electronic Calculator 130 1-1 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com SECTION 1 FRIDEN ELECTRONIC CALCULATORS 9-1-65 EC-130 SERVICE MANUAL b. REGISTER #2. One of the numbers of an arithmetic operation is in this register; the other number is in Register 1. When the numbers in these registers are used in an arithmetic opera- tion, the answer appears in Register 1, and the numbers in Register 3 and 4 are automatically shifted down by one register. ¢. REGISTERS #3 AND #4. These registers are used for storage of numbers, or intermediate answers. When the lower two registers are used for computation, these registers shift down one register with the previous Register 3 number be- ing placed in Register 2 and immediately avail- able for further computation. If Register 1 is used for an entry (or Recall, or Repeat) when all registers already contain numbers, the contents of Register 4 shift up and are effectively dis- carded, or lost. 2. KEYBOARD The keyboard (Figure 1-2) is the only mechan- ical portion of the EC-130. When a key is pres- sed, the mechanical motion of the key is trans- lated into the closing of one or more switches that initiate the electronic action of the machine. FUNCTION KEYS DIGIT ENTER key need not be used except in the enter- ing of more than one number with no other func- tions being performed between the number entries. DECIMAL POINT key is used when entering a number containing a decimal. If DECIMAL POINT key is not used, the number is sensed as a whole number and decimal aligned to the left of the deci- mal point. An automatic “Decimal Interlock” feature is provided that prevents entering more decimal digits than can be accomodated after decimal alignment. Assume a decimal point position set at 2, then only two digits to the right of the decimal point can be utilized. The third and subsequent digits entered after DECIMAL POINT key is pressed are automatically disregarded. b. FUNCTION KEYS. The function keys are designated as those keys that rearrange the data on display, or initiate arithmetic operations upon the data in Registers 1 and 2. (1) ENTER - The ENTER key completes a number entry by decimal aligning Register 1. DEC. POS. THUMBWHEEL FUNCTION KEYS KEYS Figure 1-2. Keyboard Arrangement a. DIGIT KEYS. On the keyboard are 10 digit keys (0 - 9) and a decimal point key that enable entering numbers in the machine, As a number is entered in the machine by sequential depres- sion of the digit keys, that number appears digit by digit in Register 1, but without the decimal point, The completion of a number entry is signified in the machine by pressing ENTER key, which then decimal aligns the entered number. Initia- tion of any function also aligns the number in Register 1, if not already aligned. Therefore, 1-2 (2) STORE - The STORE key places the num- ber in Register 1 into an undisplayed storage register. Once the number is stored it can be recalled as often as desired but is not changed except by replacement with a new number, or by pressing CLEAR ALL key, which removes all data. (3) RECALL - The RECALL key duplicates in Register 1 the number that is in the stor- age register. Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com 9-1-65 FRIDEN ELECTRONIC CALCULATORS SECTION 1 EC-130 SERVICE MANUAL (4) REPEAT - The REPEAT key duplicates in Register 2 the number that is in Register 1. (5) ADD (+) - The Add key initiates machine action that results in the numerical addition of the numbers in Register 1 and Register 2, with the result (answer) appearing in Register 1. When the answer appears in Register 1, numbers in Registers 3 and 4 are displayed as shifted down by one register. (6) SUBTRACT (-) - The Subtract key in- itiates machine action that results in the numerical subtraction of the number in Reg- ister 1 from the number in Register 2, with the answer appearing in Register 1 and num- bers in Registers 3 and 4 shifting down. If the number in Register 1 is larger than the number in Register 2, the subtraction still takes place. However, before display, the numerical result is complemented and then displayed with the sign changed. (7) MULTIPLY (X) - The Multiply key ini- tiates machine action that results in the numerical multiplication of the number in Register 1 by the number in Register 2 with the answer appearing in Register 1, and the numbers in Registers 3 and 4 shifting down. (8) DIVIDE (+) - The Divide key initiates machine action that results in the numerical division of the number in Register 2 by the number in Register 1, with the answer ap- pearing in Register 1 and the numbers in Reg- isters 3 and 4 shifting down by one register. c. ADDITIONAL KEYS. In addition to the digit keys and function keys are keys that initiate ma- chine operations such as clearing Register 1, clearing all data, etc. (1) CLEAR ENTRY - The CLEARENTRY key initiates machine action that results in the removal of the number in Register 1, usually in the case of a mistake being made during a number entry. (2) CLEAR ALL - The CLEAR ALL key in- jitiates machine action that results in the re- moval of all numbers from the machine. This includes any number in storage, as well as on the display. If the machine is turned off, or power to the machine is interrupted for any reason, this also results in the removal of all data. Courtesy of The Old Calculator Museum (3) CHANGE SIGN - The CHANGE SIGN key initiates machine action that results in chang- ing the sign of the number in Register 1. When a number is entered, it is sensed as a posi- tive number. Certain mathematical opera- tions involve the use of negative numbers, and the Change Sign function enables the number to be made negative after the number is en- tered. The CHANGE SIGN key also enables the sign of the number in Register 1 to be reversed at any desired point during a com- plex mathematical operation. (4) OVERFLOW LOCK - If a number that is entered, or an answer developed, contains more whole number digits than there are columns to the left of the decimal point when the number is decimal aligned by ENTER key or during a function, OVERFLOW LOCK lights up and the keyboard locks-up, which desig- nates an entry, or an answer, larger than machine capacity. The overflow condition can be cleared by any one of three keys: CLEAR ENTRY, CLEAR ALL, or OVERFLOW LOCK. CLEAR ENTRY removes the overflow by removing the number in Register 1, which is theentry, or answer, that caused the overflow. CLEAR ALL removes the overflow by clearing all numbers from the machine, which includes the entry, or answer, that caused the over- flow. OVERFLOW LOCK removes the key- board lock-up without clearing any numbers, which leaves a portion of the entry or the answer displayed in Register 1. E. DECIMAL POINT SELECTOR On the right-hand side of the keyboard is a thumb-wheel which permits selection of the col- umn position of the decimal point. There are five positions available: 0 - 2 - 5 - 7- 13. A field option is available that changes position 7 to po- sition 9. Once the decimal position is chosen with this wheel, automatic decimal alignment of all entries and answers takes place with respect to this position. F. SERVICE CALLS Many of the repairs and adjustments to the EC-130 are accomplished in the customer’s office. Following are certain servicing procedures that may prove useful, not only to the beginning tech- nician but also to the more experienced. http://oldcalculatormuseum.com SECTION ] FRIDEN ELECTRONIC CALCULATORS 9-1-65 EC-130 SERVICE MANUAL 1. CUSTOMER CONTACT A Service Technician is probably the most often seen representative of the Company, espe- cially at the office “working” level as distinguish- ed from “management”. As such, it is important that the technician be neat, well-groomed, and courteous. Competition is keen in the office equipment field. Often, the choice between competing ma- chines is the service factor. As a part of the service organization, the service technician is an important representative and should look, act, and conduct himself as such, It is not enough just to be a good technician; to know the machine; or to be able to adjust the machine satisfactorily. It is also very important to leave the customer satisfied, not only that the machine is working well, but also that he has been treated with re- spect; his wishes have been courteously received and complied with to the maximum practical ex- tent; and that the whole servicing procedure was conducted by aneat, efficient, courteous, and well- trained representative. As a part of customer contact, the technician must find out, as courteously and expeditiously as possible, the cause of customer complaint. Very often, courteous listening to the machine operator, even if not directly applicable to ma- chine malfunction, will leave a very good impres- sion. The first step in service procedure is to find out what is wrong from the standpoint of the customer. 2. MACHINE CHECKOUT Machine checkout is a series of semi-standard- ized steps used in determining a machine mal- function. Necessarily, experience with the EC- 130 will enable each service technician to develop his own checkout procedures. The following is a guide to be used if desired. a. AC POWER. Since the EC-130 is anelectronic machine, it must be furnished with AC power at 115V, 50-60 cycles from a convenient 3-wire, grounded, AC outlet. One of the first steps ina checkout is to determine if power is being fur- nished to the machine, especially if the prelimin- ary inspection reveals a blank display. On the right hand side of the machine, beneath the top cover, are two fuses. The best check of the fuses is to replace them with two known good fuses of the same type and current rating. On the bottom front right side of the machine is an On-Off switch. To turn on the machine, this switch is placed forward. The On-Off switch is interlocked with the right hand top-cover holding screw. (See Top Cover Removal and Replacement Procedure.) b. VISUAL INSPECTION. Visual inspection of the display can reveal malfunctions such as character malformation, displacement, and abnormal height or width. There are two purposes in the design of the display. One is to provide ameans of visu- ally checking the numbers to be operated with, and the second is to provide a clear and pleasing visual presentation. Certain aspects of the visual presentation are adjustable to customer satis- faction if desired. Visual display adjustments are covered in Section 3 of this manual. c. STANDARD PROBLEM. Following is astand- ard problem that will check most of the functions of the EC-130; Decimal Point Selector on0: (1) Press CLEAR ALL (2) Press digit 1-1-1-1-1-1-1 (3) Press ENTER (4) Press STORE (5) Press RECALL (6) Press REPEAT (7) Press Multiply (X) Register one shows:1234567654321 Enter, Store, Recall, Repeat, and Multiply are checked in the above procedure. (8) Press RECALL (9) Press Divide (+) Register one shows:0000001111111 Divide is checked. (10) Press REPEAT (11) Press Add (+) Register one shows:0000002222222 Add is checked. (12) Press RECALL (13) Press Subtract (-) Register one shows:0000001111111 Subtract is checked. (14) Press “0” (15) Press Divide (+) Display remains blanked. Unsolvable problem, answer would be infinity. (16) Press CLEAR ALL (17) Move Decimal Point Locator to 7 on dial. (18) Press digit: 1-1-1-1-1-1-1 (19) Press ENTER 1-4 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com 9-1-65 FRIDEN ELECTRONIC CALCULATORS SECTION 1 EC-130 SERVICE MANUAL OVERFLOW LOCK lights, keyboard locks-up. Entering of too many whole number digits is checked. (20) Press CLEAR ENTRY (21) Move Decimal Point Locator to 2 on dial. (22) Press digit: 1-1-DECIMAL POINT-1-1-1 (23) Press ENTER Register one shows: 00000000011.11 Entering of too many decimal digits is checked, G. SERVICING DOCUMENTATION In addition to the Service Manual are other documentary aids to servicing of the EC-130. They are listed and briefly explained as follows: 1. COMPUTER PRINTOUT (MDD) The computer printout is the basic engineering documentation of the EC-130. This type of docu- mentation will also be used for later machines in the design progression. As such, it contains authoritative information in a concise form that lends itself easily to changes, extraction of pro- duction information, part number and locationin- formation, and a coherent method of logic analysis by use of a specialized logic equation format. a. BASIC MDD. The Computer Printout (MDD), as reproduced for service use, contains four parts: Glossary of Terms, Logic Equations, Con- struction File, and Schematic Diagrams. (1) Glossary of Terms. The glossary lists in alphabetical order all of the logic terms used in the logic equations. The glossary further provides the number of the equation that pro- duces the term, a list of equations that con- tain this term, and a brief description of the term. (2) Logic Equations. The equations section contains the logic that produces each listed term in the glossary. The equations are written in a specialized form called “Modi- fied Polish Notation”. The equations section also contains location information in a visual coordinate system that permits the location of a signal reference point for any of the logic terms or gates referenced in a particular equation. (3) Construction File. The construction file contains production information useful in pro- viding drilling coordinates, insertion coor- dinates, lead orientation, etc. The main use of the construction file is to provide the ser- vice technician with component information on each element that makes up the logic, especially the part number of the component parts. (4) Schematic Diagrams. Certain analog cir- cuits such as the Power Supplies, Display Deflection Circuits, etc. do not lend them- selves easily to logic equation form or co- ordinate component location. Therefore, these circuits are furnished in schematic diagram form. The schematic section also contains wire lists, visual X-Y coordinate card pictures, and other information of use to the servicing technician. 2. LOGIC BLOCK DIAGRAM To aid in the training of technicians and the servicing of the EC-130, a Logic Block Diagram has been evolved from the information contained in the Computer Printout. The Logic Block Diagram contains the logic of the EC-130 in the form of gates, inverters, FF’s, and other elements. The layout of the Logic Block is primarily designed for ease of training, but is also extremely useful in servicing. The Logic Block Diagram also contains visual coordinate information to enable a servicing tech- nician to trace a logic fault back to an originating element by means of an oscilloscope in a rapid, time-saving manner. 3. ENGINEERING DRAWINGS The production of the EC-130 necessitates en- gineering drawings regarding assembly, compo- nent layout, etc. Such of these drawings as are thought useful in servicing are available as re- quested. Usually, the engineering information is furnished to the technician by means of parts lists, service letters, and service correlation of engineering drawings. 4, SERVICE LETTERS In the event that it is desired to get an engin- eering change into the field documentation im- mediately, a Service Letter is prepared contain- ing all pertinent information. The Service Letter is also used to convey special repair techniques, common trouble notes, and other servicing information of value to the technician, The Service Letter file should be well kept and each technician should be thoroughly familiar with the contents. 1-5 Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com SECTION 1 FRIDEN ELECTRONIC CALCULATORS EC-130 SERVICE MANUAL H. SERVICE RECORDS The Procedures Manual contains the latest promulgated method for handling specific service records, and other service office documents. However, the ordering of service documentation is an area of special attention. To order an engineering drawing, the engineer - ing number of the drawing must be given. To order a service produced document, the service numbering system must be used. For example, on each reproduceable page sized drawing in the Service Manual is a number such as D-130-82T. To order a drawing, this number is used. Drawing Number Format: D_ ~- Designates a drawing; A “P” would 1-6 9-1-65 designate a photograph. 130 - Model Number. 82 - Identification number in a series of numbers. T - Information and format developed by Technical Servicing Group at Home Office. An “E” would designate an en- gineering drawing which has been re- drawn by service. A “W” would desig- nate a drawing which was originated by the Technical Writing Section for use in a manual. In the event that a photograph, or less-than- page sized drawing appearing in a manual is desired, reference to the manual section and page is sufficient. Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com 9-1-65 FRIDEN ELECTRONIC CALCULATORS SECTION 2 EC-130 SERVICE MANUAL SECTION 2 - ANALYSIS OF OPERATION A. FUNCTIONAL DESCRIPTION The functional description of the EC-130 is a brief explanation of the major functional circuits on a block diagram level, with reference to the Overall Block diagram, Figure 2-1. (NOTE: Figures not in chronological order with the text are Foldouts and will be found at the end of this section.) 1. DATA ORGANIZATION The data is organized in the machine by the action of timing signals on the counters. The action of the counters controls the placement of data on the delay line, and on the CRT display. The CRT le displays datain aspecific pattern (See Figure 2-2). Some of the data relationships in the machine are not displayed but are used for necessary arith- metical, storage, or timing operations. The major time relationships in the machine are: Bit time, Register time, Column time, and Word time. a. BIT TIME. Each R time is composed of six- teen (16) Bit (B) times, of which nine (9) are used for pulses that represent digits. One B time is equal to 3 psec. b. REGISTER TIME. There are six register (R) times, of which four are displayed (See Figure 2-3). Each R time is equal ‘to 48 psec. Each register time can contain one digit of a number. 2868p SEC TIME co] ci |c2 |c3|ca|cs |ce|c7 [ce l|cs|ciofci jci2] \ to" WORD TIME — ci3}ci4|cis|co / —eo| je—a7psec. IL | 7 ‘. / START PULSE {COR3B3) 48SEC / \ [rs |ro| Ri | r2|R3 [Ra | --" 1 a, oa ' wn eect aa ' TH syste BER ces = -_—- 1 ac er el $B SSL ogGnarn iid spams ' a aren as ! ian eS < RI TIME (16 BIT TIMES) ole R2 TIME (16 BIT TIMES) + | so | 5: | 82 | 83] 54/65 | B6 aiauenwi ae a Bo] si | 82 Tee el 88 a Bi |ei2| a3 |ei4 "| BIT ; TIME 3p) SEC COUNT OF 9 COUNT OF 4 ; T | phate mci =e | \ i} ! © 0 0 00 0:0 00 00 0 0 R4 \ © 0 0 0 0 0} 0 0 0 0 0 0 O R3 0 00 00 04 0 0 0 0 0 0 R2 ! © 00 00 0989 00 00 0 0 RI 4 a a cl4 ci3 ci2 cll ClO C9 C8 C7 C6 CS C4 C3 C2 CRT DISPLAY DISPLAY TIME cl )\ pesemve FOR 1 SIGN OF REGISTER D130-29W Figure 2-2. Data Organization Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com SECTION 2 FRIDEN ELECTRONIC CALCULATORS 9-1-65 EC-130 SERVICE MANUAL cis|cialcisicizlci |ciol colca |c7lcelcs lcales |c2l cilco << CRT DISPLAY TIME | pei’ pispLay 3 DiGits)-———» ’ Lae. #————COLUMN TIME (i6 TOTAL, 4 DISPLAYED) R4_ .R3_ R2 REGISTER TIME (6 TOTAL, 4 DISPLAYED) RI RO SIGN DISPLAY Rs_ Figure 2-3. Display Organization c. COLUMN TIME. There are a total of sixteen (16) column (C) times, of which fourteen are dis- played on the CRT. Each column time is equal to 288 psec. One column (C1) is reserved for display- ing the algebraic sign of the register. Columns two (C2) through fourteen (C14) display digits for each register. Thus, a total of thirteen (13) digits may be displayed in each register. Column fifteen (C15) is used in a divide operation, and column zero (CO) is not used. d. WORD TIME. Word time is used to identify the total time available for a sequence of data. Word time consists of the six register times multiplied by fifteen column times. 2. BASIC TIMING The organization of the data on the delay line, the positioning of the data on the display, and the sequence of internal machine operations are all related exactly by timing signals from the timing circuits (See Figure 2-4), DISPLAY DISPLAY OSCILLATOR CIRCUITS COUNTER | CLOCK "B" TIME "R" TIME "Cc" TIME FF rT COUNTER COUNTER COUNTER ei "R" TIME "Cc" TIME Laer (16 "8" TIMES) (6 *R* Times) SYNC nome Le. END OF CIS TIME Figure 2-4. Timing Functional Diagram Courtesy of The Old Calculator Museum http://oldcalculatormuseum.com 9-1-65 FRIDEN ELECTRONIC CALCULATORS SECTION 2 EC-130 SERVICE MANUAL a. SYNC PULSE. To maintain the relationship between the delay line and the timing circuits, the timing chain is stopped at the end of C15 time. This begins a period of time designated as “Home”. When the machine is prepared for the entry of data after having first been turned on, or whenever all data has been cleared from the machine by CLEAR ALL key, a Sync pulse is placed on the delay line by the first function initiated by the keyboard. This Sync pulse is timed to occur before C1 time, and turns on the timing chain just before datais avail- able at the output of the delay line. This ensures that the timing chain is always in step with the data, and thus the data can be identified correctly by timing chain signals. b. CLOCK CONTROL. The basic time elementis the frequency of the oscillator. The oscillator out- put drives the clock circuit, which puts out one pulse each Bit (B) time. While the oscillator runs continuously, the output of the clock is stopped at the end of C15 time. The clockis started again by the action of the Sync pulse at the time the first data is available at the output end of the delay line. This keeps the timing chain and the data synchronized so that the timing chain signals can be used to exactly identify the data by time as it comes off the delay line; and also while it is in the counter circuits. 3. TIMING CHAIN The timing chain is agroupof FF’s that develop the basic time relationships in the machine. Tim- ing signals from the timing chain enable the data to be organized in a specific sequence and arith- metical and data shifting operations to be per- formed at specified times that are time-related to the data sequence. a. BIT TIME COUNTER. The B time counter circuits count the clock down by sixteen and pro- vide an output pulse to the Register (R) time counter every sixteen (16) B times. b. REGISTER TIME COUNTER. The R time counter circuits count down the output of the B time counter circuits by six, and provide an out- put pulse to the column (C) counter circuits every six (6) R times. c. COLUMN TIME COUNTER. The column (C) time counter circuits count down the output of the R time counter circuits by 16, and provide an out- put pulse every sixteen (16) C times. d. DISPLAY CONTROL COUNTER. The display counter provides signals to the display circuitry that enable each register to be displayed at the Courtesy of The Old Calculator Museum necessary time and proper position on the CRT. Register one (R1) is displayed twice for extra brightness and this is desirable, since the answer to an arithmetical operation always appears in this register. 4, COUNTER CIRCUITS The counter circuits perform two functions: counting and shifting. Both are basic to machine operation. Counting means to progressively change the setting of a counter by the one-by-one addition of pulses, which is called “Serial Entry”. There are two similar types of counters: Up Counter and Down Counter. They are capable of ten possible counts (settings). a. UP COUNTER. The addition of a pulse to an up counter causes the setting to change in an up- ward direction from zero toward nine. Thus, one pulse into an up counter already set to three (3) results in a new setting representing four (4). b. DOWN COUNTER. The addition ofa pulse into a down counter will cause the setting to change in a downward direction from zero (representing 10) toward one. Thus, one pulse into a down counter already set to three (3) results in a new setting representing two (2). 5. DATA SHIFTING Data shifting means to change the position of data with respect to time. To shift is to transfer the setting of one counter into another counter. Since the shift (transfer) of datais controlled with respect to time, the datacan be moved with respect to time by shifting into specified counters. Before explanation is made of the specific shifts used in machine operation, reference must be made to dataorganization with specific application to shifting. a. DATA SEQUENCE. The data organization, called “data sequence”, is by register time and column time, both on the display (Figure 2-5) and on the delay line (Figure 2-6). Note that all R times in C2 occur before the R times in C3, the R times in C3 before the R times in C4, etc. To move data from R1 to R2, the data must be stored (delayed) until R2 time occurs. To move data from R2 to R1, thedata must be moved ahead in time (advanced) because R1 occurs before R2, To move data from a register in C2 time to the same register in C3 time, the data must be delayed (stored) until that C3 time occurs. The delay or advance in time is determined by the type of shift. 2-3 http://oldcalculatormuseum.com SECTION 2 FRIDEN ELECTRONIC CALCULATORS 9-1-65 EC-130 SERVICE MANUAL | |c14|—_-—- —|es|ea|c3|calci] ci tiMe ry mt FOR SIGN R4 R3 -<— DISPLAY =~ SHIET R2 | RI | | | | Ro SHIFT ae ag) ag/ DOWN NL” SHIFT LEFT Rs TIME<— fe) Figure 2-5. Display Shifting b. SHIFT UP. To shift up means that onthe dis- play (See Figure 2-5) the registers will move up: R1 data to R2, R2 data to R38, R3 data to R4, and R4 data will be lost. However, in terms of data |» TIME c2 SHIFT SHIFT DOWN uP {\ c3 SHI